The evolution of computers and networking technologies from high-cost, low performance data processing systems to low cost, high-performance communication, problem solving, and entertainment systems has increased the need and desire for digitally storing and transmitting audio and video signals on computers or other electronic devices. For example, everyday computer users can play/record audio and video on personal computers. To facilitate this technology, audio/video signals can be encoded into one or more digital formats. Personal computers can be used to digitally encode signals from audio/video capture devices, such as video cameras, digital cameras, audio recorders, and the like. Additionally or alternatively, the devices themselves can encode the signals for storage on a digital medium. Digitally stored and encoded signals can be decoded for playback on the computer or other electronic device. Encoders/decoders can use a variety of formats to achieve digital archival, editing, and playback, including the Moving Picture Experts Group (MPEG) formats (MPEG-1, MPEG-2, MPEG-4, etc.), and the like.
Additionally, using these formats, the digital signals can be transmitted between devices over a computer network. For example, utilizing a computer and high-speed network, such as digital subscriber line (DSL), cable, T1/T3, etc., computer users can access and/or stream digital video content on systems across the world. Since the bandwidth for such streaming is typically not as large as local access and because processing power is ever-increasing at low costs, encoders/decoders often attempt to require more processing during the encoding/decoding steps to decrease the amount of bandwidth required to transmit the signals.
Accordingly, encoding/decoding methods have been developed, such as motion estimation (ME) and inter-frame prediction to provide pixel or region prediction based on a previous reference frame, thus reducing the amount of pixel/region information that should be transmitted across the bandwidth. Typically, such a scheme results in a decoding dependency, wherein each inter frame is dependent on all of its reference frames in order for proper decoding. This dependency complicates the reverse play operation and causes error propagation when video is transmitted over error prone channels.